8-hydroxy-1, 2, 3, 4-tetrahydroquinoline as a silver halide developer



, phenol.

Patented May 20, 1952 1 STATES OFF-I CE '*8 HYDRXY-1;2;3,4-TETRAHYDROQUINO- LINE AS A SILVER HALIDE DEVELOPER RobertRJBurtneUSkokie, and .Robertt la Dillon, Wilmette, 111., -assignors to"G. .'D.I Searle & 00.,

.Skokie, 111., a corporation .ofllllinois NoDravving."ApplicationSeptember-17,1947,

' "Serial- No. 774;678

This invention relates :to anew photographic developer compositions andto solutions-thereof, and to the preparation of the ;,same. Moreparticularly, the invention relates to photo rap i developercompositions containing --8-hydroxy- .l,2;3;4-etetrahydroquinoline' andhomolo gs thereof for the developmentofa latentimage inasilver halideemulsion.

It-is an object of this 'inventionto. provide dry powderphotographic'developer compositions. It isafurtherobject to-provide newdevelopingisolutions .and .baths which may betreadily prepared and whichare stable for extended periods of time. ltis still; another object-of.thisinvention to :prepare.single powder photographic developers which:contain both organic developing :agents and alkaline compounds which:are. suitable "for preparing stable aqueous-solutions. A further objectof this invention isitofproviderapidl-highenergy. develop ng solutions.

We have discoveredv that photographic developer-"compositions containing8ehydroxy+ l',2j3,4- tetrahydroquinoline and homologs thereo'f :areextraordinarily stable. in neutral and alkaline solutions, .rand produceextremely rapid photographic :developers of .;high energy. We havefurther discovered that compositions containing8-.hydroxy-1;2,3,4-tetrahydroquinoline are useful photographiccompositions in a variety'iof solutions, either alone .or in combinationwith other developing agents such as hydroquinone, pyrogallol,:catechol, paminophenol; p=methylaminophenoLo-"and p phenylenediamine,chloroh-ydro- 'quinone, "bromohydroquinone, and 'ZA-diam'ino- Other8-hydroxytetrahydroquinolines which are rsuitable ;for the preparationof photographic I-developer compositions. includ f8 hydroxy-i2-methyl-1,2,3Aetetrahydroquinoline ,iand 'BGI'IydIOXY-"G-mGthyI-'l,2,3,4 tetrahydroquinoline. The range of tones'which canbeproducedzwith photographic developer solutions. containing8-hydroxy-I,2,3,4-tetrahydroquinoline runs from brown in the weakersolutions to black in the more concentrated solutions. For this reasonthe developing solutions which comprise this invention :are particularlyuseful for developing bromide prints. Developing solutions containingfi-hydroxy 1,2,3A tetrahydroquinoline exhibit unusual stalbilityf forexample, a solutionmade with 'sodium sulfite of pH of' about 8 isstablefor at least one month. Solutions-of higher'pHare.

somewhat 'less stable, as" would be expected, but

even thosemadewith "free sodium hydroxide'have 2 tions. At higher pH'sthe 8-hydroxy-1,2:,3-,4- tetrahydroquinoline is'moresoluble, andsolutions are morereadilyprepared. Similarly, .the speed of developmentis greater at higherJT'pI-I "values than at neutrality. Inwurtdevlopercompositions," we have 'found that a variety of alkali'es 'aresuitable,such .as sodium carbonate, potassium carbonate, sodium hydroxide,trisodium phosphate, 'borax. sodium sulfite, sodium lm'etaborate andtriethanolamine. Inorganic reducing agents which have been foundsatisfactory for incorporation. into our photographic developersolutions include. sodium sulfite, sodium .bisulfite, potassiumthiocyanate, sodium thiocyanate, organic sulfinates, potassium.metabisulfite, -.and potassium ferric oxalate.

Wefhave also discovered that 8'-hydroxy-l,2 .3,4- tetrahydroquinolinescan be readilyand e'fiiciently obtained by the catalytic hydrogenationof the corresponding S-hydroxyquindlines. .Themeactions can be carriedout in any of the solvents known to besuitable for hydrogenation, suchas the lower alcohols, thelowersaturatedhydrocarbons, dioxane, certainnon-volatileethersand other inert solvents. As catalystsrwe preferto useRaney nickel because of its ready availability, convenience andefiiciency. Other nickel catalysts are also efiective, among them beingsupported nickelcatalysts such as nickel onakieselguhr. Noble metalcatalysts are suitablewalso.

among them being platinum oxide, palladium black, palladium on charcoal,platinum sponge and the like. The hydrogenation may be carried out. overa' wide range of temperature :and prossure. Forexa'mple temperatures :of20=to 1009C.

and pressures? of 20 lb..to. 500*10. 'aresuitable.

Our. invention is zfurtl'iercdisclosed .zby :the fol-'- lowing examples,which illustrate typicalneveloping solutions and compositions. Ourinvention is not. to be construed .as limited by these examples, which 3are'provided for purposes. of i'ill'ustrationonly. Itwill be apparent tolthosesk'illed in the photographic arts that a great number .ofvariations il'i'Lthe "'relative amounts of materials in the formulationsmay be made without departing from the scope of our invention.

Example 1 29 grams of fiehydroxyquinoline in, 125 .cc.. of dioxane arehydrogenated .in the presence, of Raney nickel at 20-50'lb. pressure atroom temperature in 15-20 hours. The hydrogen up-take ceases when itreaches approximately .Q.4"mo1e. Then the catalyst is removed byfiltration .and the solvent is evaporate'cl'under'reduced" pressure toabout volume. 500 cccof cold. water .are added "and 'the precipitated"'8-hydroxy'- .I;2;3,"4-

tetrahydroquinoline is"collected on afi'lter and dried. Afterrecrystallization from benzene the product melts at C.

In a similar way, B-hydroxyquinaldine can be reduced to8-hydroxy-2-methyl-1,2,3,4etetrahydroquinoline. Other solvents which aresuitable include the lower alcohols and hydrocarbons of boiling point50-150 C.

Example 2 A solution of 1.5 g. of 8-hydrdxy-l,2,3,1-tetrahydroquinolinein 10 milliliters of ethanol-is added to a solution of 25 g. of sodiumsulfite, 25 g. of

sodium carbonate and 2 to g. of potassium bromide in 800 m1. of water.After mixing, suffiv This mixture can be dissolved with slight warmingin.4 liters of water to make a stable stock developer solution which isunchanged for at 1' least a week. The dry powder may be stored for cientwater is added to bring the volume to 1 liter. The resulting clearsolution develops prints" of brownish color especially suitable for goldtones.'-

Example 3 A solution of 1 g. of 8-hydroxy-1,2,3,4-tetrahydroquinolinein10 ml. of ethanol is added to a solution of 25 g. of sodium sulfite and2 to 5 g. of potassium bromide in 500 ml. of N/10 sodium hydroxidesolution. After mixing, sufficient water is added to bring the volume to1 liter. The resulting clear solution forms brown-black prints.

Example 4 k A solution of 0.5 g. of 8-hydroxy-1,2,3,4-tetrahydroquinoline and 0.5 g. of p-methylaminophenol in 10 ml. of ethanol isadded to a solution of'25 g. of sodium'sulfite, 25 gpof sodium carbonateand 3 g. of potassium bromide in 800, ml. of water. The resultingsolution is brought to 1 liter with additional water. The clear solu-'tion is a high energy developer which produces grey-black prints.

Example 5 A solution of 0.5 g. of 8-hydroxy-1,2,3,4-tetrahydroquinolineand 0.5 g. of hydroquinone in 10 ml. of ethanol is added to a solutionof 25 g. of sodium sulfite and 2 to 5 g. of potassium bromide in'500 ml.of N/10 sodium hydroxide solution. After mixing, suflicient water isadded to bring the volume to 1 liter. This developer gives black printsof good contrast and clear whites.

Example 6 Eivample 8 A dry powder mixture is prepared by thoroughlymixing the following materials:

I Grams B-hydroxy-1,2,3,4-tetrahydroquinoline 6 Hydroquinone 24' Sodiumcarbonate monohydrate 216 Potassium metabisulfite 111 Potassium bromide'12 Sodium sulfite 90 several months without change.

Example 9 To a solution of l g. of8-hydroxy-1,2,3,4-tetrahydroquinolinein 200 ml. of N/10 sodium hydroxidesolution are added 25 g. of sodium sulfite and 5 g. of potassium bromidein 500 ml. of water. After thorough mixing the resulting clear solutionis diluted to 1 liter with water. It develops 'light-hued brown prints.

l. A photographic developing composition for the development of a.latent image in a silver halide emulsion comprising an 8hydroxy-1,2,3,4-tetrahydroquinoline and a soluble inorganic reducing agent containingtetravalent sulfur.

2. A photographic developing composition comprising anB-hydroxy-1,2,3,4-tetrahydroquinoline and sodium sulfite. v

' 3. A photographic developing composition for the development of alatent image in a silver halide emulsion comprising an8-hydroxy-1,2,3,4- tetrahydroquinoline, a hydroquinone and a solubleinorganic sulfite.

4. A photographic developing composition comprising an8-hydroxy-1,2,3,4=-tetrahydroquinoline, a hydroquinone and sodiumsulfite.

5. A photographic developing solution comprising an aqueous solution ofan 8-hydroxy- 1,2,3,4-tetrahydroquinoline and sodium sulfite.

6. A photographic developing solution, comprising an aqueous solution ofan S-hydroxy- 1,2,3, i-tetrahydroquinoline, a hydroquinone and sodiumsulfite.

.7. In a process of developing a latent image of an exposed silverhalide emulsion, the step which comprises treating said emulsion with anaqueous solution containing an 8-hydroxy-,1,2,3,4- tetrahydroquinolineand a soluble inorganic reducing agent containing tetravalent sulfur.

8. In aprocess of developing a latent image of an exposed silver halideemulsion, the step which comprises treating said emulsion with anaqueous solution containing an 8-hydroxy-1,2,3,4 tetrahydroquinoline, ahydroquinone and a so1u ble inorganic sulfite.

9. In a process of developing a latent image of an exposed silver halideemulsion, thestep-which comprises treating said emulsion with an aqueoussolution containing an 8-hydroxy-1,2,3,4-.tetrajhydroquinoline andsodium sulfite. v1'

ROBERT R. BURTINERQ ROBERT T. DILLON.

REFERENCES CITED Y The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 'Date Sease et al Aug. 31, 1943

1. A PHOTOGRAPHIC DEVELOPING COMPOSITION FOR THE DEVELOPMENT OF A LATENTIMAGE IN A SILVER HALIDE EMULSION COMPRISING AN8-HYDROXY-1,2,3,4TETRAHYDROQUINOLINE AND A SOLUBLE INORGANIC REDUCINGAGENT CONTAINING TETRAVALENT SULFUR.